Patent GB-396739-A (GB)
Title: Improvements in automatic switches for use in telephone or like systems
IPC: H01H67/16
Filed: 1932-02-09
Abstract: 396,739. Automatic exchange switches. AUTOMATIC ELECTRIC CO., Ltd., Strowger Works, and WOODLAND, C. R., 45, Warnerville, Broadgreen, both in Liverpool. Feb. 9, 1932, No. 3876. [Class 40 (iv).] The controlling relays and operating magnets of a bidirectional switch are both mounted on the same side of a substantially plane supporting plate which also carries the wiper shaft. The wipers are carried by a carriage which moves up and around the wiper shaft and the stepping mechanism is mounted within the planes of the contact banks. The mechanicallyoperated spring sets are all mounted on separate brackets projecting from the main supporting plate, all the brackets being in the same horizontal plane. The contact banks are mounted independently of the switch and can be withdrawn for inspection when necessary. As shown in Figs. 1 and 2, the main supporting plate 10 carries the vertical and rotary magnets 19, 18 and the controlling relays. The fixed wiper shaft 12, which is supported by the plate 10 and by a bridge-piece 11, carries the carriage comprising vertical ratchet 17, rotary ratchet 15, and wiper sets 9, which are fixed to the carriage by screws 8. During vertical motion, the carriage is held by the detent 27 (see Fig. 6) and during rotary motion the carriage is supported by the comb cut on 16 and is held in position by the detent 31 which is constructed as a single unit with detent 27. The switch is normally returned to normal by movement to the twelfth rotary position whence it falls to normal vertical position and then restores to the rotary normal, both movements being under action of the spring 33, but if rotary release only is desired the rotary detent is provided with an extension which engages the vertical pawl so that, after rotary motion has taken place, re-operation of the vertical magnet releases the rotary detent. The teeth in the vertical ratchet are cut deeper than those in the rotary ratchet to enable the vertical detent to hold the switch' against vertical release under these conditions. A combined vertical and rotary backstop member 21 is provided which can be adjusted by the screws 50, 51 for the rotary control and by bending for the vertical position. The mechanically-operated springs are mounted in line across the front of the switch as indicated in Fig. 3 and each set is secured to a bracket which passes through a slot in the frame plate and fastens to the platform at the rear. In the Figure the vertical and rotary interrupter springs are shown on the extreme right and left of the plate, the eleventh step springs are operated by the roller 36 which engages the comb plate 16, the offnormal springs are operated by the lever 38, the normal post springs by buffers 39 secured to the comb plate in the appropriate position and the rotary off-normal springs by the cam plate 41 which engages the lever 42. The contact banks are threaded on pillars 47, Fig. 5, which are fastened between the shelves 48, 49. The banks, with the pillars 47, may be withdrawn from the rear for inspection purposes by removing the screws shown, the pillars being then held in position by the spring links 50, 51.